This project concerns choice processes in behavioral allocation and persistence in persons with intellectual disabilities. It will have two related foci. The first will be focus on children with severe intellectual disabilities. With regard to formal analysis of basic behavioral processes involved in behavioral allocation and persistence, this population has been virtually unstudied. It is not known, for example, whether such children will exhibit relatively greater insensitivity to consequential variables than those with less severe disabilities; determining this relationship would have clear implications for designing treatment programs and/or for interpreting their results. The second focus will be on the potential impact of social variables on processes involved in behavioral allocation and persistence. This too is a little studied area, particularly with children with severe disabilities. Studies will be conducted to assess the degree to which social variables may influence processes involved in behavioral allocation and persistence. To conduct the studies, we will employ a unique computer-controlled automated teaching environment that has been especially designed to meet the needs of children with severe intellectual disabilities. Within it, the child can acquire substantial new behavior independently; it is not necessary to have a teacher physically present during teaching. This unique characteristic will make it possible to study behavioral allocation and persistence under conditions that feature an unprecedented degree of control of social variables. In parallel with the laboratory studies, we plan a program of studies within the special education classroom. This parallel program will serve as a contrast to the laboratory program, investigating the degree to which basic research findings are consistent with those obtainable in less structured settings. Consistent with the overall theme of this program project, Project 1 has been motivated by an extensive body of empirical research and theory that has only recently begun to influence research in the MR/DD field. Our primary motivations are: (a) extensive quantitative analyses that have led to mathematical relations that describe behavioral allocation in choice situations; (b) "behavioral momentum" theory, which relates certain basic concepts of physical motion to behavior, and (c) "percentile" methods for developing new behavior, an algorithmically-based application of quantitative analysis to what has heretofore been a largely qualitative art (the gradual shaping of new behavior).